The window of the invention may be included in window configurations with traditional awning opening style, that is to say, windows that rotate about a horizontal axis on traditional hinges, or in the field of traditional awning windows known in the jargon of the trade as “top hung” windows.
Hereinafter, this specification will describe prior art solutions derived from the top hung window but without limiting the scope of the invention to top-hung windows with traditional awning opening style, that is to say, with hinges configured to make the movable frame rotate outwards about a horizontal axis with its bottom rail.
Awning window units, usually made of metal, PVC or the like and of wood, are used for airing rooms and the parts of the windows inside the rooms are often equipped with accessories such as fly screens. In addition, to comply with safety regulations in the countries in which these window units are most widely used, these window units must have controlled opening with a limit on the angle achievable by the movable frame moving away from the fixed frame.
The window unit basically comprises:                a fixed frame;        a movable frame connected to the fixed frame usually by        a pair of hinged arms interposed between the respective vertical stiles of the two frames;        an operating unit located on the rail of the fixed frame and acting on the lower rail of the movable frame to allow the movable frame to move away from the fixed frame (that is to say, controlled opening of the movable frame) and also to allow the movable frame to return in contact with the fixed frame;        an element for stably closing the movable frame on the fixed frame, the element usually being located on a fixed frame stile and acting on the respective stile of the movable frame for stabilising closing.        
As is known also from document U.S. Pat. No. 4,726,092, which describes a hinged arm solution for casement windows but which might also be applied to awning windows of the type according to this invention, each hinged arm may comprise:}                a support stably associated with the respective fixed frame stile and close to a fixed frame corner zone;        a first connecting arm hinged, at its ends, to the support and, respectively, to the end of a second arm which is associated with the stile of the movable frame to allow the opening and closing movements.        
The opposite, free end of the second arm is connected to a slide inserted in the support, which also allows the movable frame to slide along the two fixed frame stiles, rendering movable frame opening a rotating—translating movement with the lower rail of the movable frame moved away from the lower rail of the fixed frame.
The operating unit or rotor, designed to control movable frame opening and closing, may comprise, normally and in prior art solutions as is also shown in documents U.S. Pat. No. 7,464,619 or CN 101131061, a housing unit for a control shaft, the unit being fixed on the outer edge of the lower rail of the fixed frame.
The control shaft has an inner portion equipped with a mechanism usually comprising helical toothing designed to mesh with a respective helical toothing or semi-toothing made around an operator arm pivot point inside the housing unit.
The operator arm is interposed between the lower rails of the fixed frame and of the movable frame and is articulated, at its free end, to the rail of the movable frame.
The control shaft protrudes from the housing unit for connecting with a handle which is fixed or preferably applied by the user when necessary, thus allowing movable frame movement by manually turning the handle.
Obviously, the presence of the connecting point between the operator arm and the movable frame provides a low security closing seal, therefore, a second element is added, such as the above-mentioned stable closing element.
A first solution is known from document GB 2.183.723 where two handles control two L-shaped links which, by turning, are accommodated in respective housings in the movable frame in order to lock the movable frame when the latter is in the closed position.
The handles are located on the bottom fixed rail or on the fixed stile (depending on the control unit on the window and on the type of window it is mounted on).
In another prior art solution described in document US 2008250719, the closing element substantially comprises a lock handle applied on the fixed frame stile and connected to a rod sliding along the inner part of the stile.
Therefore, the purpose of the rod is to form a connecting element between the movable frame and the fixed frame and it can usually be fitted with one or more strikers which, when the movable frame is closed, engage respective rollers or retaining elements present on the movable frame stile, resulting in stable closing of the window unit.
A window unit structured in that way has revealed disadvantages due to the separate structure of the operating and closing units.
As may be inferred from the above description, assembly of the operating unit requires complex machining on the outer profile (through-slots) of the fixed frame and, above all, machining also on the inner part of the fixed frame to allow the hinged arms and the closing elements on the stiles to coexist. The presence of both necessitates machining on the thicknesses of the stiles to make the window unit accessible for these closing elements (possibly even in a superposed position).
Added to this is the further need for machining on the outside stiles of the window unit (in particular through-slot openings) for allowing the insertion of the closing element.
Therefore, basically a window unit structured in that way is complex to make and so is expensive overall, as well as having complex operation as far as the user is concerned (obliged to go through various steps to open and close the window).